XML : android:background="@drawable/bg" causes program to crash

When I add android:background="@drawable/bg" to my code, it causes the program to crash. When i remove it however, it works fine. What is wrong? I have even tried the layout.setBackground() and layout.setBackgroundDrawable() ways and they all cause the program to crash.

  <?xml version="1.0" encoding="utf-8"?>  <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"      android:id="@+id/bg"      android:layout_width="fill_parent"      android:layout_height="fill_parent"      android:background="@drawable/bg"      android:orientation="vertical">          <LinearLayout          android:layout_width="fill_parent"          android:layout_height="fill_parent"          android:orientation="vertical">            <LinearLayout              android:id="@+id/linearlayout1"              android:layout_width="fill_parent"              android:layout_height="fill_parent"              android:layout_weight="1"              android:orientation="vertical">            </LinearLayout>            <LinearLayout              android:layout_width="fill_parent"              android:layout_height="wrap_content"              android:orientation="vertical">                <TextView                  android:id="@+id/textView2"                  android:layout_width="fill_parent"                  android:layout_height="wrap_content"                  android:layout_gravity="center_horizontal"                  android:gravity="center_vertical|center_horizontal"                  android:text="inScope"                  android:textSize="30dp" />                <LinearLayout                  android:layout_width="match_parent"                  android:layout_height="wrap_content"                  android:layout_weight="0"                  android:orientation="vertical">                    <EditText                      android:id="@+id/emailfield"                      android:layout_width="fill_parent"                      android:layout_height="wrap_content"                      android:layout_gravity="center_vertical"                      android:layout_weight="0"                      android:background="@android:color/transparent"                      android:hint="Email" />                    <EditText                      android:id="@+id/passwordfield"                      android:layout_width="fill_parent"                      android:layout_height="wrap_content"                      android:layout_gravity="center_vertical"                      android:layout_weight="0"                      android:background="@android:color/transparent"                      android:ems="10"                      android:hint="Password"                      android:inputType="textPassword"                      android:paddingTop="20dp" />              </LinearLayout>          </LinearLayout>            <LinearLayout              android:id="@+id/linearlayout2"              android:layout_width="fill_parent"              android:layout_height="226dp"              android:orientation="horizontal">                <Button                  android:id="@+id/login"                  android:layout_width="wrap_content"                  android:layout_height="wrap_content"                  android:layout_weight="1"                  android:singleLine="false"                  android:text="Login"                  android:theme="@style/Base.Widget.AppCompat.Button.Borderless" />                <Button                  android:id="@+id/register"                  android:layout_width="wrap_content"                  android:layout_height="wrap_content"                  android:layout_weight="1"                  android:text="Register"                  android:theme="@style/Base.Widget.AppCompat.Button.Borderless" />          </LinearLayout>      </LinearLayout>  </LinearLayout>